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Biomedical subjects

H Shimada

Publications and source records attributed to H Shimada.

At least 379 records · Page 21Linked to original sources
PubMed1997

Direct assessment of triploid cells in mosaic human fetuses by fluorescence in-situ hybridization.

Villous tissues from 30 spontaneous abortions and the same number of artificial abortions were obtained and analysed for the frequency of polyploid cells. Single cell suspensions were made from these tissues without culture and the ploidy of > 100 cells was analysed. Trisomies of chromosomes 17 and 4 have rarely been reported in villous cells of spontaneous abortions, suggesting that the presence of more than three copies of chromosomes 17 and 4 per cell indicates polyploidy. The number of chromosomes 17 and 4 was detected by fluorescence in-situ hybridization analysis using centromeric probes D17Z1 and D4Z1. Most villous cells from cases of spontaneous and artificial abortions had two D17Z1 or D4Z1 signals per cell, with very small percentages of cells (0.5 +/- 0.4%) showing three signals per cell. However, in four cases of spontaneous abortions, 2-12% of cells had three D17Z1 or D4Z1 signals per cell. This indicates the presence of triploid cells in these cases of spontaneous abortion, at a significantly higher frequency compared to artificial or the remaining 26 cases of spontaneous abortion. In addition, three cases contained 0.2-0.4% of cells showing six signals, indicating that these cells were dividing triploid cells. The low frequency of mosaicism reported here would not be detectable by conventional chromosomal analysis.

Abortion, Induced↗
PubMed1997

Mitochondrial damage by a new antitumour agent furanonaphthoquinone derivative in human cervical cancer HeLa cells.

The intracellular ultrastructural changes induced by the new antitumour agent 2-methylnaphtho[2,3-b]furan-4,9-dione (FNQ3) were investigated in human cervical cancer HeLa cells in comparison with normal cervix cells. The normal cells were isolated from cervixes surgically resected from myoma patients and were keratin positive. FNQ3 at 3-5 micrograms ml-1 selectively damaged the HeLa cell mitochondria followed by rough-surfaced endoplasmic reticulum resulting in cell death. In contrast, normal cells remained unaffected at that concentration but were damaged by 20 micrograms ml-1 FNQ3. The FNQ3-induced tumour cell toxicity was inhibited 52% and 36% by trolox and a water-soluble fraction of the antioxidative substance AOB, respectively. The results indicated that FNQ3 is selectively toxic to HeLa cells at approximately eight times that of normal cells in terms of mitochondrial alteration and free radical formation.

Antineoplastic Agents, Phytogenic↗
PubMed1997

Nucleotide sequence and transcriptional analysis of the flanking region of the gene (spb) for the trans-acting factor that controls light-mediated expression of the puf operon in Rhodobacter sphaeroides.

We recently reported the existence of a trans-acting factor (SPB) in Rhodobacter sphaeroides that repressed the expression of the puf operon during illumination. SPB was somewhat homologous to HvrA of Rhodobacter capsulatus, but these proteins appear to have functionally different properties. We now report an analysis of the flanking region of spb in the genome of R.sphaeroides, and we show that spb is a positional counterpart of hvrA of R. capsulatus. The region directly downstream of spb was found to contain three genes, two of which were highly homologous to orf5 and ahcY in R. capsulatus. However, a gene corresponding to hvrB, which controls the expression of orf5 and ahcY in R. capsulatus, was absent in R. sphaeroides. The level of the transcript of ahcY did not change in cells grown under photosynthetic and by respiratory conditions. By contrast, orf5 was transcribed at a higher rate in photosynthetically grown cells under high-intensity light than under low-intensity light, indicating features of transcription different from those in R. capsulatus. A third gene, orf318, which was absent in the corresponding region of R. capsulatus, encoded an amino acid sequence that was significantly homologous to the consensus sequence of RfaI and RfaJ of E.coli, which are glycosyl transferases involved in the synthesis of lipopolysaccharide. orf318 was transcribed in the opposite direction to ahcY, and at only a low level, under all conditions tested.

Amino Acid Sequence↗
PubMed1997

Factors affecting neostigmine reversal of vecuronium block during sevoflurane anaesthesia.

We examined the influence of the concentration of sevoflurane and the degree of muscle block at the time of reversal on the activity of neostigmine. Ninety ASA 1-2 patients were anaesthetised with 0.2, 0.7 or 1.2 MAC of sevoflurane (30 patients each) in 66% nitrous oxide in oxygen. The electromyographic (EMG) response of the adductor digiti minimi was monitored at 20-s intervals after train-of-four stimulation of the ulnar nerve. The initial neuromuscular block was produced by vecuronium 100 micrograms.kg-1. When the amplitude of the first response (T1) values had recovered to 10%, 25% or 40% of the control, neostigmine 40 micrograms.kg-1 was administered. The train-of-four ratio values were recorded at 1-min intervals during the subsequent 15-min period. Higher endtidal concentrations (p < 0.0001) and more pronounced block at the time of reversal (p < 0.0001) were associated with a delayed recovery in the train-of-four ratio. In addition, the train-of-four ratio 15 min after neostigmine administration was more dependent on the sevoflurane concentration than on the degree of block present (p < 0.0001). These results confirm that neostigmine (40 micrograms.kg-1) can reverse vecuronium-induced but not sevoflurane-induced neuromuscular block.

Adult↗
PubMed1997

Histological localization of advanced glycosylation end products in the progression of diabetic nephropathy.

We studied the immunohistochemical localization of advanced glycosylation end products (AGEs) in the progression of diabetic nephropathy. Fourteen NIDDM patients with diabetic nephropathy were evaluated: 2 patients with normoalbuminuria, 4 with microalbuminuria (MA) and 8 with overt proteinuria (OP). Three patients with minor glomerular abnormalities were used as nondiabetic controls. Immunoreactivity to a monoclonal anti-AGE antibody (6D12) was recognized on the internal elastic membranes of arterial walls in every diabetic group. Hyaline lesions of arterioles of the MA and OP groups demonstrated strong reactions with 6D12. A portion of the nodular and exudative lesions in glomeruli of OP group patients also revealed immunoreactivity to 6D12. No immunoreactivity to 6D12 was observed in nondiabetic control specimens. We confirm that the accumulation of AGEs began in arterial walls of the early stage and presented in glomerular lesions of the late stage of the progression of diabetic nephropathy.

Adult↗
PubMed1997

Toxic interactions between disopyramide and propranolol in chick embryos.

The toxic interaction between disopyramide and propranolol were studied in chick embryos. Fertilized eggs of White Leghorns were incubated and investigated. Disopyramide with and without propranolol was injected into the air sac of a fertilized egg on the 16th day of incubation. Electrocardiograms (ECGs) were recorded 0 to 60 min after the injection. After each drug injection alone, the heart rate was not different compared with control. However, the heart rate was significantly decreased by combination with disopyramide and propranolol. In addition, arrhythmia was produced by disopyramide 1.0 mg/egg alone and in combination with propranolol. These findings indicate that the interaction between disopyramide and propranolol has a marked influence on the heart rate in chick embryos.

Animals↗
PubMed1997

Inhibitory mechanisms of oleanolic acid 3-O-monodesmosides on glucose absorption in rats.

We examined the action mechanism of oleanolic acid 3-O-monodesmoside, momordin Ic (1), and oleanolic acid 3-O-glucuronide (2) for the inhibitory effect on the increase in serum glucose levels in oral glucose-loaded rats. Although 1 and 2 dose-dependently inhibited the increase in serum glucose levels in oral glucose-loaded rats, these compounds showed no significant effects on serum glucose levels in normal rats, intraperitoneal glucose-loaded rats, and alloxane-induced diabetic mice. Furthermore, 1 and 2 were found to suppress gastric emptying in rats, and also to inhibit the glucose uptake in rat small intestine concentration dependently in vitro. These results indicate that 1 and 2 given orally have neither insulin-like activity nor insulin releasing-activity. 1 and 2 apparently inhibited glucose absorption by suppressing the transfer of glucose from the stomach to the small intestine and by inhibiting the glucose transport system at the small intestinal brush border.

Animals↗
PubMed1997

Medicinal foodstuffs. VII. On the saponin constituents with glucose and alcohol absorption-inhibitory activity from a food garnish "Tonburi", the fruit of Japanese Kochia scoparia (L.) Schrad.: structures of scoparianosides A, B, and C.

The methanolic extract of a food garnish "Tonburi", the fruit of Japanese kochia scoparia (L.) Schrad. (Chenopodiaceae), was found to inhibit the increase in serum glucose-loaded rats. Through bioassay-guided separation, momordin Ic and its 2'-O-beta-D-glucopyranoside were isolated as the active principles from this medicinal foodstuff together with three new saponins named scoparianosides A, B, and C. The structures of scoparianosides A, B, and C were elucidated on the basis of chemical and physicochemical evidence as 3 beta, 22 alpha-dihydroxyolean-12en-28-oic acid (22 alpha-hydroxyoleanolic acid), 3-O-beta-D-xylopyranosyl (1 --> 3)-beta-D-glucopyranosiduronic acid, 3 beta-hydroxyolean -18-en-28-oic acid (morolic acid), 3-O-beta-D-xylopyranosyl(1 --> 3)-beta-D -glucopyranosiduronic acid, and 3 beta-hydroxyolean-13(18)-en-28-oic acid, 3-O-beta-D-xylopyranoxyl(1 --> 3) -beta-D-glucopyranosiduronic acid. Momordin Ic and its 2'-O-beta-D-glucopyranoside, both of which are the principal saponin constituents of this medicinal foodstuffs, were found to potently inhibit glucose and ethanol absorption in rats.

Animals↗
PubMed1997

Bioactive constituents of Chinese natural medicines. IV. Rhodiolae radix. (2).: On the histamine release inhibitors from the underground part of Rhodiola sacra (Prain ex Hamet) S. H. Fu (Crassulaceae): chemical structures of rhodiocyanoside D and sacranosides A and B.

The methanolic extract of the underground part of Rhodiola sacra (PRAIN ex HAMET) S. H. Fu was found to show inhibitory activity on the histamine release from rat peritoneal exudate cells induced by an antigen-antibody reaction. From the methanolic extract with the inhibitory activity on histamine release, a new cyanoglycoside called rhodiocyanoside D and two new monoterpene glycosides called sacranosides A and B were isolated, together with eight known compounds, rhodiocyanoside A, heterodendrin, lotaustralin, rhodioloside, 2-phenylethyl alpha-L-arabinopyranosyl(1-->6)-beta-D-glucopyranoside, 2-methyl-3-buten-2-yl beta-D-glucopyranoside, kenposide A, and rhodiooctanoside. The structures of new compounds were determined on the basis of chemical and physicochemical evidence, which included the synthesis of sacranoside A from (-)-myrtenol. All major chemical constituents from R. sacra inhibited the histamine release and, among them, lotaustralin and rhodiooctanoside were found to show potent inhibitory activity.

Animals↗
PubMed1997

Medicinal foodstuffs. V. Moroheiya. (1): Absolute stereostructures of corchoionosides A, B, and C, histamine release inhibitors from the leaves of Vietnamese Corchorus olitorius L. (Tiliaceae).

Three new ionone glucosides named corchoionosides A, B, and C were isolated from the leaves of Corchorus olitorius, commonly called "moroheiya" in Japanese, together with seven known compounds, an ionone glucoside (6S,9R)-roseoside, a monoterpene glucoside betulalbuside A, two flavonol glucosides astragalin and isoquercitrin, two coumarin glucosides scopolin and cichoriine, and chlorogenic acid. The absolute stereostructures of corchoionosides A, B, and C were determined by chemical and physiochemical evidence, which included the result of application of a modified Mosher's method, the CD helicity rule, and chemical correlation with (6S,9R)-roseoside. Corchoionosides A and B and (6S,9R)-roseoside were found to inhibit the histamine release from rat peritoneal exudate cells induced by antigen-antibody reaction.

Animals↗
PubMed1997

Medicinal foodstuffs. VI. 1) Histamine release inhibitors from kidney bean, the seeds of Phaseolus vulgaris L.: chemical structures of sandosaponins A and B.

Two new olean-12-ene-type triterpene oligoglycosides, named sandosaponins A and B, were isolated from kidney bean, the seed of Phaseolus vulgaris L., together with three known saponins, soyasaponins I and V and dehydrosoyasaponin 1. The structures of sandosaponins A and B were determined on the basis of chemical and physicochemical evidence, which included the chemical derivation of sandosapogenol from a known sapogenol, soyasapogenol B. Five saponins obtained from kidney bean were found to inhibit histamine release from rat exudate cells induced by an antigen-antibody reaction and, among them, sandosaponins A and B showed the most potent inhibitory activity.

Animals↗
PubMed1997

A comparison of the uricosuric effects in rats of diltiazem and derivatives of dihydropyridine (nicardipine and nifedipine).

The effects of nicardipine and nifedipine on the urinary excretion of urate were examined in rats and compared with those of diltiazem. Test drugs were administered to urethane-anesthetized oxonate-loaded rats by continuous i.v. infusion. Diltiazem (10 micrograms/rat/min), nicardipine (0.3 microgram/rat/min) and nifedipine (1.0 microgram/rat/min) caused similar reductions of systemic blood pressure and increased total renal blood flow. Diltiazem did not increase urine volume significantly. However, this drug produced obvious uricosuria, with a significant increase in the ratio of urate clearance to inulin clearance (Cua/Cin), which resulted from an increase in Cua, but not from changes in the glomerular filtration rate (GFR). Nicardipine had clear diuretic and uricosuric effects, with similar increases in Cua and GFR and, thus, no change in Cua/Cin. On the other hand, nifedipine did not have any significant effect on the renal handling of urate. These results suggest that nicardipine produces uricosuria in rats via alterations in renal hemodynamics, while the uricosuric effect of diltiazem involves the tubules, as well as alterations in renal hemodynamics.

Animals↗
PubMed1997

Cloning of cyclin E cDNA of the sea urchin, Hemicentrotus pulcherrimus.

cDNA encoding maternal cyclin E (HpCycE) has been cloned from the oocyte cDNA library of the sea urchin, Hemicentrotus pulcherrimus, by differential screening with a cDNA probe covering the total poly(A)+ RNAs of 16 cell-stage embryos and gastrulae. In this communication we describe similarity of amino acid sequences between HpCycE and those of cyclin E from other organisms and maternal origin of HpCycE. The amino acid sequence deduced from the nucleotide sequence of HpCycE cDNA is highly similar to those of human, rat, chicken, Xenopus, zebrafish and Drosophila, while its similarity to other cyclins is much lower. A gene for HpCycE exists as a single copy in the genome of H. pulcherrimus. Northern blotting revealed that the mRNA for HpCycE is maintained at a high level up to the morula stage and thereafter declines.

Animals↗
PubMed1997

Severity of coronary artery calcification detected by electron beam computed tomography is related to the risk of restenosis after percutaneous transluminal coronary angioplasty.

To assess the relationship between coronary artery calcification and the late success rate of percutaneous transluminal coronary angioplasty (PTCA), we performed electron beam computed tomography (EBCT) in 22 patients with ischemic heart disease who underwent PTCA. The calcification score in each coronary artery vessel was estimated and compared with the occurrence of restenosis at 3 months after PTCA. Angioplasty had been performed in 28 sites in 22 patients, and 12 sites exhibited restenosis. The mean calcium score in the unsuccessful PTCA vessels was significantly higher than in successful sites (228 vs 92). The overall late success rate of PTCA with moderate to severe calcification was extremely low at 29%. Coronary segments with diffuse and extensive calcification were not optimal target lesions for PTCA. Prediction of the late success rate after PTCA may be possible by prior evaluation of coronary artery calcification utilizing EBCT.

Aged↗
PubMed1997

Anti-inflammatory and ulcerogenic effects of 3-(N,N-diethylamino) propylindometacin HCl.

AIM: To study anti-inflammatory effects of a novel indometacin ester, 3-(N,N-diethylamino) propyl-indometacin HCl (prodrug) and its ulcerogenicity in fats. METHODS: Carrageenin (Car)-induced paw edema and ulcer index were examined. RESULTS: Car-induced paw edema was inhibited by 36.6% (P < 0.01) at 3 h and 34.6% (P < 0.01) at 5 h after a single i.p. injection of the prodrug 7.09 mg.kg-1. On the same molar basis, indometacin (Ind) 5 mg.kg-1 i.p. inhibited edema by 45.6% at 3 h and 39.2% at 5 h, however, there was no statistical significant difference (P > 0.05) between the edema-inhibitory effect of the prodrug and that of Ind. The dose 10 micrograms/paw exhibited 64% inhibition of the swelling, the prodrug > 10 micrograms/paw showed no additional inhibition of swelling; the acute gastric lesion properties of the prodrug were much lower than those of Ind 6 h after p.o. CONCLUSION: The prodrug is a potent anti-inflammatory agent with lower ulcerogenicity in the stomach.

Animals↗
PubMed1997

[Esophageal cancer and multiple primary cancer].

Two hundred eleven cases, 27.1%, of multiple primary cancers of esophagus and other organs were found in 778 cases of esophageal cancers which were treated in our institution. Among them, double cancer accounted for 92.9%, triple cancer accounted for 6.6% and quadruple cancer for 0.5%. As for the other organ of esophageal double cancer. 59.9% of them were head and neck, 25.1% were stomach, 4.9% were colon and rectum, and remaining included liver, breast, lymphoma lung kidney etc. Head and neck cancers consisted with hypopharynx, tongue, larynx, oral floor and gingiva regarding incidence in its order. For discovering of double cancer in esophagus and other organs, 1. head and neck, stomach, colon and rectum, lung, liver etc. should be investigated preoperatively in the patients of esophageal cancer, 2. Esophagus should be examined preoperatively in the patients of these cancers, 3. Screening of esophageal cancer should be performed in the patients of high risks of esophageal cancer. As for the multiple primary cancer of esophagus and other organs, the balance of treatment should be considered to take the priority of the cancer limiting the prognosis.

Adult↗
PubMed1997

[Pleural B cell lymphoma presenting as paraplegia].

A 54-year-old man felt pain on the right side of his chest. Two months later, paraplegia developed. A chest CT scan revealed a pleural effusion and a mass lesion along the right parietal pleura. The lesion extended directly into the adjacent part of the spinal canal and compressed the spinal cord. Cytologic examination of the pleural effusion revealed atypical lymphoid cells, and examination of a transcutaneous biopsy specimen showed monotonous atypical B lymphocytes. The diagnosis was pleural malignant lymphoma. Chemotherapy induced a partial remission, but 14 months after the first examination he died of central nervous system involvement. Pleural lymphoma can directly compress the spinal cord and cause paraplegia. Early diagnosis and therapy greatly affect the outcome in patients with spinal cord compression.

Humans↗